MDchanic

Hello, all.

A quick (?) question about exhaust manifolds:

Which ones (from which cars) will fit a '71 to '75 B-body?

My '73 88 currently has a 260 in it, and it was originally a 350 car, so either way, it's got SB manifolds.
I just picked up a 425 which I'll be freshening up a bit, but it was pulled from a '68 Cutlass, and has '68 Cutlass SB manifolds (#1 and #4, if I recall) on it.

I've reviewed the numbers in the Parts Manual, but as we know, just because a certain number was used in one particular year doesn't mean that other numbers won't fit fine as well.
The CO and 442.com FAQs don't get up to the later cars.

I'd like to be fairly confident that I've got the right ones in advance, rather than trying to fit the engine in and going "D'oh!"

Thanks in advance,

- Eric

rocketraider

W & Z, same as the A-body car for 71-74. If you can't find originals, they're reproduced.

You can use these on a 75 or 76 without catalytic converter, and you would need a 71-74 crossmember if you do away with it.

MDchanic

That's what I wanted to know - A-body will fit.

I should also try to clarify one other thing:
I am under the impression that earlier (up to '72) A-body manifolds will fit later (post '72) A-bodies.
Does this mean that early A-body manifolds will fit later B-bodies as well? Or is that all a bunch of hooey?

Thanks,

- Eric

2blu442

Eric, my experience has been a little different than rocketraider's. I've had a couple of these engines and they had an X on the drivers side (open plenum, not the same as A-body X manifolds) and I believe a letter T on the passengerside with a crossover. They won't breath as good as the W/Z manifolds but would be much cheaper. Here's a picture of the drivers side:

P1010114.jpg

P1010116.jpg


Then here's a 1968 455 with the letter T passengerside manifold.
P1010535.jpg

2blu442

I have seen W/Z manifolds that I believe came factory on a 1973 Cutlass, but can't speak for the B-body. John

MDchanic

Ah. But, to clarify, you've got photos of a pre-'71 B-body motor there -
Would the manifolds be the same, considering the front end differences between the two models (rear-steer vs front-steer, etc.)?

Not to be a PITA, but the guides seem to stop at the '71 models, and I just want to be as clear as I can on this.

- Eric

ps: for added fun, 406301 is listed as "????" in the 442.com database, and isn't listed AT ALL (check me on this) in the parts manual.
This is why I'm checking to make sure.

2blu442

Good morning Eric
Over the years I've had 4 or 5 engines with the 406301 manifold. In the back of the garage I have the 455 that came out of a 1971 Delta Custom. It has this manifold on it, and I believe the T for the passengerside. I'll have to move some clutter to reach it but can verify that after work one day this week if that would help. So it will fit with the crossover or you could cap that off and run dual exhaust. That said, your small block manifolds should fit too. They won't flow as well, but if you need to run with them a while you could. I'm pretty sure the crossover pipe and ports out the back are in the same location. I think the primary difference is the internal size of the two. If it would help I can set the two size by side and take some photos/measurements for you.

A couple years ago I suggested updating the wiki site with this reference for the 406301 manifold. I don't know if that was done or not. John

J-(Chicago)

I agree with John on this one.
65-67 were A/T
and 68-72 were (open)X/T for single exhaust.

The w/z combo probably was available if you wanted dual exhaust. My basic rule of thumb.... if it fit in the 68-72 cutlass', there's a 90% chance it will fit in the deltas either the same, or much easier.

I am not sure about 73-76, but to me, there's not much difference between a 71 or a 76.

rocketraider

Just going by what the 1974 edition parts book calls for, as it was contemporary with the cars. It says same p/n for A/B/C body 455 dual exhaust, and I've successfully used W/Z on a couple of early 70s B cars.

zodiacblueS

Another tidbit. From what I know, which is minimal, the X manifolds were not the same in early versions as they were in 73-74. Attached pics show the X manifold that came on my 73 S w/455 without an open plenum. It's chambered like the Z manifold. I think that this X was used on all the big cars then.
Just my $.02 worth.

MDchanic

Interesting.

Thanks.

- Eric